SPF Test Debate Sizzles

By: Nancy Jeffries

Posted: October 10, 2008, from the February 2006 issue of GCI Magazine.

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“Consumers are confused by multiple SPF numbers, especially the highest numbers that can’t be confirmed by different laboratories,” said Stanfield. “And the ambiguity of UVA and broad spectrum claims and terms such as ‘water resistant’ and ‘very water resistant.’ I believe more effort should go into formulating cosmetically attractive products that consumers find easy to use and don’t have to pay large sums of money for. And I’d like to see new and better sunscreen ingredients and innovation in the science of sun protection.”

FDA Responds

Matthew Holman, interdisciplinary scientist and team leader, FDA, and Susan Cruzan, press office, FDA, say effectiveness testing of over-the-counter (OTC) sunscreen products currently is limited to SPF testing, representing protection against sunburn caused primarily by UVB radiation. “The SPF test has been used in the United States since the 1970s,” said Cruzan. “The FDA has modified it slightly over the past 30 years to incorporate scientific and technical advances and improve accuracy and reproducibility. However, the SPF value on OTC sunscreen products today still represents the same protection measurement that consumers have come to know and understand over the past three decades.

“In the future, the FDA will propose effectiveness testing against UVA radiation,” continued Cruzan. “Scientific studies suggest UVA radiation causes long-term skin damage, such as skin cancer and premature skin aging. Currently, OTC sunscreen manufacturers can test their products for UVA protection by a number of methods published in scientific journals. If an OTC sunscreen product demonstrates effectiveness, then it can be labeled as ‘broad spectrum,’ ‘provides UVA/UVB protection’ or similar claims.”

The FDA is developing a proposal that will require a specific UVA test method and UVA labeling. “After the FDA develops the proposal, we will publish it in the Federal Register, and the public will have the opportunity to comment on it. After reviewing the comments, the FDA will then publish a final rule on UVA testing and labeling. This final rule will have an effective date, after which OTC sunscreen manufacturers will have to comply with the FDA’s UVA testing and labeling,” Cruzan said.

Measurement Approaches

Dieter Kuster, CEO and senior chemist, CA Botana, said in vivo and in vitro testing provide very different measurement approaches. “In vivo testing is less and less common because of total spectrum UVB and UVA, whereby UVA is the longer wavelength and cancer causing, which in most cases shows after several years of consistent exposure to sunlight without protection,” he stated. “Those waves are present from sunrise to sunset, and will penetrate through windows. UVB, the most common wave, is a shorter wave, but will show irritation and, consequently, a burnt condition.” Kuster noted in vitro testing seemed safer, with the sun protection factor determining the amount of protective ingredients used.